Who Is at Risk for Antiphospholipid Antibody Syndrome?

Antiphospholipid antibody syndrome (APS) can affect people of any age. The disorder is more common in women than men, but it affects both sexes.

APS also is more common in people who have other autoimmune or rheumatic disorders, such as lupus. ("Rheumatic" refers to disorders that affect the joints, bones, or muscles.)

About 10 percent of all people who have lupus also have APS. About half of all people who have APS also have another autoimmune or rheumatic disorder.

Some people have APS antibodies, but don't ever have signs or symptoms of the disorder. The mere presence of APS antibodies doesn't mean that you have APS. To be diagnosed with APS, you must have APS antibodies and a history of health problems related to the disorder.

However, people who have APS antibodies but no signs or symptoms are at risk of developing APS. Health problems, other than autoimmune disorders, that can trigger blood clots include:

Smoking

Prolonged bed rest

Pregnancy and the postpartum period

Birth control pills and hormone therapy

Cancer and kidney disease

Source: National Heart, Lung, and Blood Institute, National Institutes of Health